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Diffstat (limited to 'iredis/data/commands/object.md')
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diff --git a/iredis/data/commands/object.md b/iredis/data/commands/object.md index e5321f7..887ab9d 100644 --- a/iredis/data/commands/object.md +++ b/iredis/data/commands/object.md @@ -1,80 +1,3 @@ -The `OBJECT` command allows to inspect the internals of Redis Objects associated -with keys. It is useful for debugging or to understand if your keys are using -the specially encoded data types to save space. Your application may also use -the information reported by the `OBJECT` command to implement application level -key eviction policies when using Redis as a Cache. +This is a container command for object introspection commands. -The `OBJECT` command supports multiple sub commands: - -- `OBJECT REFCOUNT <key>` returns the number of references of the value - associated with the specified key. This command is mainly useful for - debugging. -- `OBJECT ENCODING <key>` returns the kind of internal representation used in - order to store the value associated with a key. -- `OBJECT IDLETIME <key>` returns the number of seconds since the object stored - at the specified key is idle (not requested by read or write operations). - While the value is returned in seconds the actual resolution of this timer is - 10 seconds, but may vary in future implementations. This subcommand is - available when `maxmemory-policy` is set to an LRU policy or `noeviction` and - `maxmemory` is set. -- `OBJECT FREQ <key>` returns the logarithmic access frequency counter of the - object stored at the specified key. This subcommand is available when - `maxmemory-policy` is set to an LFU policy. -- `OBJECT HELP` returns a succinct help text. - -Objects can be encoded in different ways: - -- Strings can be encoded as `raw` (normal string encoding) or `int` (strings - representing integers in a 64 bit signed interval are encoded in this way in - order to save space). -- Lists can be encoded as `ziplist` or `linkedlist`. The `ziplist` is the - special representation that is used to save space for small lists. -- Sets can be encoded as `intset` or `hashtable`. The `intset` is a special - encoding used for small sets composed solely of integers. -- Hashes can be encoded as `ziplist` or `hashtable`. The `ziplist` is a special - encoding used for small hashes. -- Sorted Sets can be encoded as `ziplist` or `skiplist` format. As for the List - type small sorted sets can be specially encoded using `ziplist`, while the - `skiplist` encoding is the one that works with sorted sets of any size. - -All the specially encoded types are automatically converted to the general type -once you perform an operation that makes it impossible for Redis to retain the -space saving encoding. - -@return - -Different return values are used for different subcommands. - -- Subcommands `refcount` and `idletime` return integers. -- Subcommand `encoding` returns a bulk reply. - -If the object you try to inspect is missing, a null bulk reply is returned. - -@examples - -``` -redis> lpush mylist "Hello World" -(integer) 4 -redis> object refcount mylist -(integer) 1 -redis> object encoding mylist -"ziplist" -redis> object idletime mylist -(integer) 10 -``` - -In the following example you can see how the encoding changes once Redis is no -longer able to use the space saving encoding. - -``` -redis> set foo 1000 -OK -redis> object encoding foo -"int" -redis> append foo bar -(integer) 7 -redis> get foo -"1000bar" -redis> object encoding foo -"raw" -``` +To see the list of available commands you can call `OBJECT HELP`. |